Acid-responsive fibrillation and urease-assisted defibrillation of phenylalanine: a transient supramolecular hydrogel. Issue 44 (6th August 2020)

• Record Type: Journal Article
• Authors: Mondal, Sahabaj; Podder, Debasish; Nandi, Sujay Kumar; Roy Chowdhury, Srayoshi; Haldar, Debasish
• Is Part Of: Soft matter. Volume 16:Issue 44(2020)
• Page Start: 10115
• Page End: 10121
• Publication Date: 2020-08-06
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d0sm00774a
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : A mimic of living systems has been achieved by the acid-responsive assembly and urease-assisted disassembly of fibrils from benzyloxycarbonyl-l -phenylalanine, leading to a transient supramolecular hydrogel. Abstract : The aggregation of proteins and peptides into fibrils is associated with many neurodegenerative diseases in humans, including Alzheimer's disease, Parkinson's disease and non-neurological type-II diabetes. A better understanding of the fibril formation process and defibrillation using biochemical tools is highly important for therapeutics. Under physiological conditions, acidic pH promotes the formation of toxic fibrils. Here, a mimic of living systems has been achieved by the acid-responsive assembly of benzyloxycarbonyl-l -phenylalanine to fibrils, as well as the urease-assisted disassembly of the said fibrils. The simultaneous incorporation of the two triggers helped to prepare a transient supramolecular hydrogel from benzyloxycarbonyl-l -phenylalanine-entangled fibrils with a high degree of control over the self-assembly lifetime and mechanical properties. Further, under acidic pH, the compound formed the O–H⋯OC hydrogen-bonded dimer. The dimers were further self-assembled by intermolecular N–H⋯OC hydrogen bonds and π–π stacking interactions to form fibrils with high mechanical properties, from this simple molecule. However, the self-assembly process is dynamic. Hence, the in situ -generated NH3 uniformly increased the pH and led to the homogeneous disassembly of the fibrils. Thus, this report provides a valuable approach to defibrillation.